Revert of Pass --images '' to nanobench to disable image benchmarking.

tools/nanobench_flags.json

Index: tools/nanobench_flags.json
diff --git a/tools/nanobench_flags.json b/tools/nanobench_flags.json
index 4f669e1fe5839bd5411c6ac0af9e3b39ca5aa310..6084ad1609985549bdd86d1f8bfe93e1890e7adb 100644
--- a/tools/nanobench_flags.json
+++ b/tools/nanobench_flags.json
@@ -1,6 +1,5 @@
 {
   "Perf-Android-GCC-NexusPlayer-GPU-PowerVR-x86-Release": [
-    "--images", 
     "--scales", 
     "1.0", 
     "1.1", 
@@ -18,7 +17,6 @@
     "~desk_unicodetable"
   ], 
   "Perf-Android-Nexus7-Tegra3-Arm7-Release": [
-    "--images", 
     "--scales", 
     "1.0", 
     "1.1", 
@@ -37,7 +35,6 @@
     "~desk_carsvg"
   ], 
   "Test-Android-GCC-GalaxyS4-GPU-SGX544-Arm7-Release": [
-    "--images", 
     "--scales", 
     "1.0", 
     "1.1", 
@@ -55,7 +52,6 @@
     "~GLInstancedArraysBench"
   ], 
   "Test-Ubuntu-GCC-ShuttleA-GPU-GTX550Ti-x86_64-Release-Valgrind": [
-    "--images", 
     "--scales", 
     "1.0", 
     "1.1", 
@@ -74,7 +70,6 @@
     "1"
   ], 
   "Test-Win7-MSVC-ShuttleA-GPU-HD2000-x86-Debug-ANGLE": [
-    "--images", 
     "--scales", 
     "1.0", 
     "1.1", 
@@ -96,7 +91,6 @@
     "~etc1bitmap"
   ], 
   "Test-iOS-Clang-iPad4-GPU-SGX554-Arm7-Debug": [
-    "--images", 
     "--scales", 
     "1.0", 
     "1.1",